AT49F001-90TC Equivalent & Substitute Parts

Part Overview

The AT49F001-90TC is a 1Mbit parallel FLASH memory IC manufactured by Microchip Technology, housed in a 32-TSOP package with 90 ns access time. This device is classified as obsolete, making substitute components necessary for new designs and production continuity. The part operates within the 4.5V to 5.5V supply voltage range and supports standard parallel memory interface protocols typical of legacy embedded systems and industrial applications.

Substiute Parts

AT49F001-90TC

Microchip TechnologyIn Stock: 855AT49F001-90TC Datasheet

Current PartRFQ

SST39SF020A-55-4C-WHE

Microchip TechnologyIn Stock: 2768SST39SF020A-55-4C-WHE Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

The SST39SF020A-55-4C-WHE qualifies as a functional substitute based on the following alignment of critical parameters:

Electrical Compatibility:

• Identical voltage supply range (4.5V ~ 5.5V)
• Identical operating temperature range (0°C ~ 70°C)
• Parallel memory interface maintained
• Compatible 32-TSOP package footprint

Performance Characteristics:

• Access time of 55 ns is faster than the original 90 ns specification, ensuring backward compatibility
• Write cycle time of 20µs is faster than the original 50µs, improving performance
• Memory organization differs (256K x 8 vs. 128K x 8), providing double the capacity

Compliance & Status:

• Active product status ensures long-term availability
• RoHS3 compliant, meeting modern regulatory requirements
• Identical MSL rating (3, 168 Hours)

Parameter Comparison

Engineering Selection Recommendations

The SST39SF020A-55-4C-WHE is suitable as a direct substitute for the AT49F001-90TC based on electrical and mechanical compatibility. The substitute part maintains identical supply voltage and operating temperature specifications, ensuring seamless integration into existing circuit designs. The faster access time and write cycle time provide performance improvement without introducing compatibility issues.

The substitute part's active product status and RoHS3 compliance address the obsolescence of the original component and align with current manufacturing and environmental standards. The increased memory capacity (2Mbit vs. 1Mbit) provides additional functionality without requiring circuit modifications, provided the application firmware supports the expanded address space.

Frequently Asked Questions (FAQ)

Q: Can the SST39SF020A-55-4C-WHE directly replace the AT49F001-90TC without circuit modifications?

A: Yes. Both parts share identical voltage supply ranges (4.5V ~ 5.5V), operating temperature ranges (0°C ~ 70°C), parallel memory interface architecture, and 32-TSOP package footprint. The substitute's faster access time and write cycle time are backward compatible with designs specified for the original part.

Q: What is the primary difference between these two parts?

A: The SST39SF020A-55-4C-WHE provides double the memory capacity (2Mbit vs. 1Mbit) with improved performance metrics. Access time is reduced from 90 ns to 55 ns, and write cycle time is reduced from 50µs to 20µs.

Q: Are there any compliance differences between the original and substitute parts?

A: Yes. The AT49F001-90TC is RoHS non-compliant and obsolete. The SST39SF020A-55-4C-WHE is RoHS3 compliant and maintains active product status, ensuring long-term availability and compliance with current environmental regulations.

Q: Does the increased memory capacity require firmware changes?

A: The substitute part's expanded address space (256K x 8 vs. 128K x 8) is transparent to the parallel interface protocol. Firmware modifications are required only if the application intends to utilize the additional memory capacity beyond the original 1Mbit address range.

Q: Are the package dimensions identical?

A: Both parts use 32-TSOP surface mount packages. The AT49F001-90TC package width is 18.40mm, while the SST39SF020A-55-4C-WHE package width is 12.40mm. Both are compatible with standard 32-TSOP PCB footprints, though the substitute part has a smaller physical footprint.